Salini Impregilo has won a US$1.3bn (£930m) contract to build villas and associated infrastructure for the Saudi Arabia National Guard.

The project involves major housing and urban planning work, including the construction of 6,000 villas in an area covering seven million square metres to the east of Riyadh.

Work also includes building a main road more than 160km long together with secondary routes and related services such as a sewage treatment plant. The contract is expected to be completed in five years.